金枪鱼共附生菌Streptomyces sp.TUN21的次级代谢产物研究

海洋动物共附生微生物次级代谢产物是海洋药物的重要来源。该文从金枪鱼共附生菌Streptomyces sp.TUN21的次级代谢产物中分离得到3个化合物,分别为campechic acid B(1),5-(3’-aminophenyl)-2,4-pentadienoic acid(2)和benzenemethanol(3)。其中化合物1对PC-3和HCT-116的抑制活性的IC_(50)值分别为(1.3±0.2)μmol和(0.64±0.1)μmol,而化合物2是首次从该属中分离得到的天然产物。化合物1~3在50μg/mL的浓度下对耐甲氧金黄色葡萄球菌、大肠杆菌和白色念珠菌无抑制活性。

Streptomyces sp.DJ菌株产生的角蛋白酶的序列分析

【目的】解析Streptomyces sp.DJ菌株编码的3种角蛋白酶的氨基酸序列、二级结构、三级结构及其功能的关系。【方法】基于DJ菌株全基因组测序结果,利用Bio-edit、DNAMAN、Discovery Studio2.5等软件、https://swissmodel.expasy.org/等网站对其3种角蛋白酶的序列和结构进行了分析和预测。【结果】DJ菌株胞外分泌3种角蛋白酶(K1、K2和K3)均属于S8家族的丝氨酸蛋白酶,信号肽、前导肽和成熟肽在氨基酸残基的组成、极性和长度等方面较一致。3种酶均能以5WSL.1.A为模板进行同源建模,每种酶的3-D结构中均含有6个α螺旋、2个3_(10)α螺旋和15个β折叠的二级结构;其中K1酶含有2个二硫键,1Ca和2Ca位点,K2和K3各有1个二硫键,1Ca位点;3种酶的Pro270残基位于loop环,而仅有K2的Pro242残基位于loop环中。3种酶底物结合区域主要由疏水性残基构成,偏向于疏水性强的底物。3种酶的底物结合区域比较而言,S1和S2对底物特异性起关键作用;由于3种酶的S1和S2中重要位点残基的不保守性,使其底物特异性具有差异。【结论】DJ菌株中3种角蛋白酶在氨基酸、二硫键、脯氨酸和钙结合等的不同致使酶稳定性的不同;并且由于其表面电荷分布、底物结合区域的差异构成对羽毛水解位点的互补性,这可能是DJ菌株高效降解羽毛的重要原因。

Streptomyces sp.N2所产农抗N2对桔青霉的拮抗活性及作用机制研究

【目的】Streptomyces sp.N2是本课题组分离筛选到的一株可产新型抗真菌活性物质(3-甲基-3,5-氨基-4-烯-吡喃-2-酮,分子式为C6H7O2N,农抗N2)的新种,此活性物质对桔青霉具有良好的拮抗效果。从生长特征、细胞形态学等角度,为揭示农抗N2在桔青霉生长发育中的抑菌作用机理奠定基础。【方法】首先采用常量培养基稀释法测定了农抗N2对桔青霉的最低抑菌浓度、杯碟法测定了不同浓度农抗N2对桔青霉的抑菌活性菌丝和生长量法测定了不同浓度农抗N2对桔青霉生长曲线的影响,并通过扫描电镜及透射电镜探究了农抗N2对桔青霉超微结构的影响。【结果】Streptomyces sp.N2所产农抗N2对桔青霉有较强的抑制作用,而且其机理初步判定为破坏桔青霉菌丝的菌丝结构,推迟了桔青霉对数期的到来而抑制菌体的生长。菌体最低抑菌浓度(3 d)为5.77μg/mL,其对应的抑菌圈大小为(13.04±1.06)mm。药液处理后,桔青霉生长对数期推迟了2 d。由扫描电镜以及透射电镜结果可推测,农抗N2可干扰桔青霉细胞壁合成,破坏细胞膜结构,致使细胞发生质壁分离。【结论】农抗N2对桔青霉的菌丝生长具有很强的抑制作用,且具有浓度效应,其对桔青霉的形态和结构有很大的破坏作用,可以推测农抗N2能够影响桔青霉细胞壁相关蛋白的合成,使细胞壁的通透性增强,影响其细胞膜及内部细胞器。

Streptomyces sp. RP1A-12 mediated control of peanut stem rot caused by Sclerotium rolfsii

Sclerotium rolfsii Sacc. is a destructive soilborne fungal pathogen with a wide host range that includes peanuts. Biological control offers an interesting alternative to fungicides for sustainable management of soilborne diseases. The current investigation is aimed at evaluating one potential biocontrol agent Streptomyces sp. RP1 A-12 for growth promotion and the management of peanut stem rot disease caused by S. rolfsii under field conditions. Preliminary studies conducted under in vitro and the greenhouse conditions showed promising results against the stem rot pathogen. Further in vitro and pot experiments conducted to assess Streptomyces sp. RP1 A-12 for its growth promoting abilities using whole organisms have shown an increase in seed germination, root and shoot length. Other parameters like nodule number and plant biomass were also significantly increased over control treatments indicating that the test bioagent possesses growth promoting abilities along with disease suppression capabilities. Subsequently field studies were carried out for two consecutive rainy seasons. The bioagent was applied as whole organism and partially purified crude metabolites. Results indicate the bioagent reduced stem rot disease incidence by 64–67% and 22–49% respectively in two field trials conducted with notable increase in yield. Partially purified Streptomyces sp. RP1 A-12 metabolites exhibited an even greater effect in reducing the incidence and severity of stem rot compared to the pathogen inoculated control.

A New Degraded Sesquiterpene from Marine Actinomycete Streptomyces sp. 0616208

A new degraded sesquiterpene was isolated from the marine actinomycete Streptomyces sp. 0616208. Its structure was elucidated as （1α; 4aα; 5α, 7β, 8aβ）-5, 8a-dimethyl-decahydrona- phthalene-1, 4a, 7-triol on the basis of spectroscopic data.

Bioactive Compounds Produced by Streptomyces sp. Isolate UPMRS4 and Antifungal Activity against Pyricularia oryzae

A Streptomyces isolate having antifungal activity against Pyricularia oryzae, the causal agent of rice blast disease, was isolated from soil collected in rice fields of Tanjung Karang Selangor, peninsula Malaysia.The aim of the study was to determine the antifungal activity of Streptomyces sp. isolate UPMRS4 extracts against P. oryzae and to identify bioactive antifungal compounds produced by UPMRS4. Various solvents were used for extraction of antifungal compounds and well diffusion method was used to determine the antifungal activity of the extracts. The ethyl acetate extract demonstrated the highest activity against mycelial growth of P. oryzae, with an effective inhibitory concentration (EIC) of 1.562 μg/ml significantly higher compared to that of chloroform, diethyl ether, methanol, acetone, ethanol and water. Based on GC-MS and LC-MS/MSanalyses,compounds with antifungal activity were detected such as (Pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl);Pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(phenylmethyl);ergotamine;amicomacin;fungichromin;rapamycin and N-Acetyl-D, L-phenylalanine. These compounds had good general antifungal activity and might have potential future agricultural applications.

Antimicrobial and antiproliferative prospective of kosinostatin-a secondary metabolite isolated from Streptomyces sp.

Cancer is a communal health hazard worldwide. The present investigation attempts to evaluate anti- microbial and anticancer potential of kosinostatin on mammary carcinoma cell line （MCF-7）. The anticancer and antiproliferative activities of kosinostatin were analyzed on MCF cell line by MTT assay and cytotoxicity assays like lactate dehydrogenase （LDH） and glutathione （GSH）. The secondary metabolite kosinostatin exhibited its apoptotic nature by expressing p53 protein. Collectively, the results acquired from this study promise that kosinostatin shows the potent anticancer activity.

Multi-Omics-Guided Discovery of Omicsynins Produced by Streptomyces sp.1647:Pseudo-Tetrapeptides Active Against Influenza A Viruses and Coronavirus HCoV-229E

Many microorganisms have mechanisms that protect cells against attack from viruses.The fermentation components of Streptomyces sp.1647 exhibit potent anti-influenza A virus(IAV)activity.This strain was isolated from soil in southern China in the 1970s,but the chemical nature of its antiviral substance(s)has remained unknown until now.We used an integrated multi-omics strategy to identify the antiviral agents from this streptomycete.The antibiotics and Secondary Metabolite Analysis Shell(antiSMASH)analysis of its genome sequence revealed 38 biosynthetic gene clusters(BGCs)for secondary metabolites,and the target BGCs possibly responsible for the production of antiviral components were narrowed down to three BGCs by bioactivity-guided comparative transcriptomics analysis.Through bioinformatics analysis and genetic manipulation of the regulators and a biosynthetic gene,cluster 36 was identified as the BGC responsible for the biosynthesis of the antiviral compounds.Bioactivity-based molecular networking analysis of mass spectrometric data from different recombinant strains illustrated that the antiviral compounds were a class of structural analogues.Finally,18 pseudo-tetrapeptides with an internal ureido linkage,omicsynins A1–A6,B1–B6,and C1–C6,were identified and/or isolated from fermentation broth.Among them,11 compounds(omicsynins A1,A2,A6,B1–B3,B5,B6,C1,C2,and C6)are new compounds.Omicsynins B1–B4 exhibited potent antiviral activity against IAV with the 50%inhibitory concentration(IC_(50))of approximately 1μmol·L^(-1)and a selectivity index(SI)ranging from 100 to 300.Omicsynins B1–B4 also showed significant antiviral activity against human coronavirus HCoV-229E.By integrating multi-omics data,we discovered a number of novel antiviral pseudo-tetrapeptides produced by Streptomyces sp.1647,indicating that the secondary metabolites of microorganisms are a valuable source of novel antivirals.

Control Efficacy of Streptomyces sp. SY-L12 and Chitooligosaccharide on Kiwifruit Bacterial Canker, Pseudomonas syringae pv. actinidiae

[ Objective] The paper was to develop a priority scheme for prevention and control of kiwifruit bacterial canker with biological agents. [ Method ] The inhibitory effect of Streptomyces sp. SY-L12 on the growth of Pseudomonas syringae pv. actinidiae were assessed using liquid co-culture and inhibition zone meth- ods. The control efficiency of Streptomyces sp. fermentation broth against kiwifruit bacterial canker was studied via potted trial. [ Result ] As Streptomyces sp. SY- L12 was incubated for 24 h, the growth inhibition rate of its fermentation broth on P. syr/ngae pv. actinidiae was 94.0%. The control efficiency of fermentation broth against P. syringae pv. actinidiae was the best of 85.4% in potted trial when Streptomyces sp. SY-L12 grew at 28~C, 150 rpm for 8 -9 d, better than that of control agent copper hydroxide. The control efficiency was improved as the agent was mixed with 1 mg/L chitooligosaccharide. [ Conclusion] Streptomyces sp. SY-L12 could effectively inhibit the growth of P. syr/ngae pv. actinidiae, and can be developed as biological agent against kiwifruit bacterial canker.

A New Virginae Butanolide from Streptomyces sp.

A novel butanolide, named virginaebutanolide F （1）, was isolated from the lyophilized culture broth of Streptomyces sp., along with a known compound virginaebutanolide C （2）. Their structures including the stereochemistry were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS and CD spectroscopic analysis.

Bioactive Compound from Streptomyces sp. KB1 TISTR2504 as Effective Disinfectant against Microorganisms

A host environment cleaning using disinfectants is the most effective way to prevent the pathogen’s transmission.This study compared the activity among of commercial liquid disinfectants[3%hydrogen peroxide(HP),and 70%ethyl alcohol(EA)]and bioactive-compounds(BCs)from Streptomyces sp.KB1 on indicating microorganisms:Bacillus subtilis ATCC 6633 as representative of spores;Staphylococcus aureus TISTR 517 and clinical methicillin-resistant S.aureus as representative of gram-positive bacteria,Escherichia coli TISTR 887,Pseudomonas aeruginosa TISTR 1467,and extended spectrum beta-lactamase(ESBL)-Klebsiella pneumoniae 342 as representative of gram-negative bacteria;Candida albicans TISTR 5779 as representative of yeast.Results showed that B.subtilis spores are resistant to 70%EA and BCs from strain KB1-which are biocidal to TISTR strains and clinical isolate MRSA,ESBL-in the free floating microorganism(suspension test).On the other hand,this resistance was not observed with 3%HP.Thus,3%HP showed more promise for disinfecting microorganisms than that 70%EA and BCs.However,BCs did show the antimicrobial activities equal as 70%EA.The results might be implied that the using of BCs from selected bacterial strain as effective disinfectant against microorganism,especially vegetative cell,is a sustainable application in nearly future,to reduce using the chemical substances and zero wastes.

链霉菌株Streptomyces sp.FXP04对水稻种子萌发和幼苗生长的影响

为了明确链霉菌株Streptomyces sp.FXP04对水稻的促生效果,以前期筛选到的链霉菌株Streptomyces sp.FXP04为供试菌株,采用发酵液浸种和菌液喷洒土壤的方法,研究了该菌株生长稳定期的发酵液和菌液对水稻种子萌发和幼苗生长的影响。结果如下,培养皿试验中,Streptomyces sp.FXP04发酵液原液和LB培养液原液(对照)都抑制种子萌发,1/50倍发酵液显著促进种子萌发,而1/10倍和1/100倍发酵液对种子萌发没有显著影响。盆栽试验中,1/50倍和1/100倍的Streptomyces sp.FXP04菌液都促进了水稻种子萌发,增加了水稻幼苗株高、主根长、干重、根总长度、须根数、根表面积和根总体积,并且1/50倍菌液的促生效果和1/100倍菌液无显著差异。研究结果表明,链霉菌株Streptomyces sp.FXP04对水稻种子萌发和幼苗生长有促进作用,可作为水稻的候选促生菌株开展后续研究和应用。

Antibiotic Metabolites from the Coral-Associated Actinomycete Streptomyces sp. OUCMDZ-1703

From the oligotrophic culture of a soft coral-associated actinomycetes strain, Streptomyces sp. OUCMDZ-1703, we isolated and identified two new chlorinated polyketides that we named strepchloritides A and B （1 and 2）, three thiazole derivatives known as watasemycin A （3）, pulicatin G （4） and aerugine （5）, along with pyrrole- 2-carboxamide, furan-2-carboxamide and 1-（3,5-dihydroxyphenyl）ethanone. The new structures of 1 and 2 were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses, while the known compounds were identified by comparison of the NMR data with those in literatures. The results showed that actinomycete strain OUCMDZ-1703 could use the relative high ratio of chlorine in the oligotrophic medium to synthesize chlorinated natural products. New compounds 1 and 2 displayed cytotoxicity against the MCF-7 ceils with ICs0 values of 9.9 and 20.2 ~tmoloL-1, respectively. Thiazole derivatives 3 and 5 were first found to be active against three clinical strains of methicillin-resistant Staphylococcus aureus （MRSA082, MRSA111 and MRSA234） with the same MIC/MBC values of 7.81/7.81 μg·mL-1.

Neopeapyran, an unusual furo[2,3b]pyran analogue and turnagainolide C from a soil Streptomyces sp. S2236

Neopeapyran（1）,an unusual furo[2,3b]pyran analogue,together with a new cyclopeptide,turnagainolide C（2）,were isolated from Streptomyces sp.S2236 associated with the rhizosphere soil of Panax notoginseng.The planar structure and relative configuration of neopeapyran（1） were elucidated on the basis of spectroscopic techniques,while the absolute configuration was determined by TDDFT calculation.The absolute configuration of turnagainolide C（2） was determined by partial hydrolysis,together with the advanced Marfey’s method and spectroscopic analysis.The antimicrobial activities of these two compounds were also investigated.

Application of statistical design for the production of inulinase by streptomyces sp. using pressmud

A Plackett-Burman design was employed for screening 18 nutrient components for the production of inulinase using streptomyces sp.and pressmud as the substrate via solid-state fermentation(SSF).From the experiments,three nutrients viz.yeast extract,FeSO_(4)·7H_(2)O,and NH4NO3 were found to be the most significant components.Hence these three components were selected and optimized using Response Surface Methodology(RSM).The optimum conditions are:yeast extract 0.00274 g/gds,FeSO_(4)·7H_(2)O 0.00011 g/gds and NH4NO30.00772 g/gds.The effect of the substrate concentration and initial moisture content were also studied.A substrate concentration of 12 g and an initial moisture content of 65%are optimum for the maximum production of inulinase(89 U/gds).

17-[16,17-Dihydroxycyclooctatinyl]-hexaketide ester from Streptomyces sp. SR107

A new hexaketide acid esterified by the 17-hydroxyl group of 16,17-dihydroxycyclooctatin, namely 17-[16,17-dihydroxycyclooctatinyl]-hexaketide ester(1), a member of the group of rare bacterial diterpenes with a fused 5-8-5 ring system was isolated from strain Streptomyces sp. SR107. The structure was determined on the basis of its spectral data(~1H NMR, ^(13) C NMR, ~1H-~1H COSY, HSQC, HMBC, NOESY, IR and HR-ESI-MS). The antibacterial activity was also evaluated in this paper.

Shunt products of aminoansamycins from aas1 overexpressed mutant strain of Streptomyces sp.S35

Constitutively expression of the pathway-specific activators is an effective method to activate silent gene clusters and improve natural product production.In this study,nine shunt products of aminoansamycins(1-9)were identified from a recombinant mutant strain S35-LAL by overexpressed the large-ATP-binding regulator of the LuxR family(LAL)gene aas1 in Streptomyces sp.S35.All the compounds showed no anti-microbial,anti-T3 SS and cytotoxic activities.

A potent fish pathogenic bacterial killer Streptomyces sp.isolated from the soils of east coast region,South India

Objective:To investigate the potentiality of the marine actinobacteria isolated from marine soil against fish pathogenic bacteria.Methods:east coast region(ECR)of Tamilnadu,South India.Then they were used for the isolation of actinobacteria by using conventional serial dilution technique on starch casein agar medium.The antibacterial activities of the actinobacteria were screened primarily by using cross streak plate method against fish pathogenic bacteria namely Vibrio alginolyticus,Vibrio parahaemolyticus,Vibrio cholera,Aeromonas sp.and Pseudomonas sp.The antimicrobial efficacy of the selected isolates was carried out with various organic solvents,and finally the active compound was subjected to chromatographic techniques including TLC and GC-MS.Results:In the present study,a total of 33 soil samples were collected from the Bay of Bengal,against fish pathogenic bacteria.Out of 21 antibacterial isolates,the isolate ECR77 was selected for further study based on its potential activity against fish pathogenic bacteria.Of the various solvents tested,the ethyl acetate extract had good antibacterial activity against the tested bacterial pathogens.The isolate ECR77 grew well on oat meal agar medium with 2%salt level at 35°C.GC-MS study found that the presence of bioactive compounds namely tetradecanoic acid,n-hexadecanoic acid and octadecanoic acid.The morphological,physiological,biochemical and cultural characteristics of the potential isolate were supported the identity up to generic level asStreptomyces sp.ECR77.Conclusions:The results obtained from this study concludes that the ECR soils of South India is a hot spot of novel bioactive compound producing marine actinobacteria with great pharmaceutical values.Of the 82 actinobacteria isolated,21(26%)isolates were possessed antibacterial activity.

Screening for a new Streptomyces strain capable of efficient keratin degradation

Keratinous wastes could be degraded by some microorganisms in nature. Native human foot skin （NHFS） was used as sole nitrogen source to screen microorganisms with keratin-degrading capability. From approximately 200 strains, a strain of Streptomyces sp. strain No. 16 was found to possess the strongest keratinolytic activity, and the total activity in the culture was 110 KU/ml with specific activity of 2870 KU/mg protein （KU： keratinase unit）. Substrate specificity test indicated that the crude keratinase could degrade keratin azure, human hair, cock feathers and collagen. The optimal pH of the crude keratinase ranged from 7.5 to 10 and the temperature ranged from 40℃ to 55℃. Metal chelating agent ethylenediamine tetraacetic acid obviously stimulated the keratinolytic activity but suppressed the proteolytic activity. To our knowledge, this is the first report on specific induction of keratinases by NHFS from an actinomycete. Moreover, excellent characteristics of its crude keratinase may lead to the potential application in waste treatment and recovery, poultry and leather industry, medicine, and cosmetic development.

Isolation, purification and structure elucidation of three newbioactive secondary metabolites from Streptomyces lividans AM

Microorganisms are a huge mine of bioactive metabolites,and actinomycetes are one of the very active groups in this area.In this article,we are concerned about the full taxonomical characterization of Streptomyces lividans AM,isolated from Egyptian soil.This isolate produced three new bioactive metabolites,namely:1-Nona-decanoyl,4-oleyl disuccinate(1),filoboletic acid;(9Z,11E)-8,13-dihydroxy octadeca-9,11-dienoic acid(2),and sitosteryl-3β-D-glucoside(3).Extensive 1D and 2D NMR and HR-mass spectrometry were used to elucidate the structures of the three compounds.Moreover,ten known compounds were also identified.The antimicrobial activity of the producing organism and newly reported compounds(1–3)was investigated against a selected group of pathogenic microorganisms.A full taxonomical characterization of the strain was described as well.